基于应力流理论的垂、横向刚度解耦型浮轨扣件理论设计方案研究OA

The traditional floating rail fastener is widely used due to its low vertical stiffness,which can achieve a high vibration damping effect.However,its low lateral stiffness results in a large transverse dynamic displacement.In order to improve the transverse load resistance of the floating rail fastener,a refined finite element model of the fastener was established based on its actual dimensions,and the fastener structure was optimized using stress flow theory as the fundamental principle and the load transfer path as the design basis.The vertical and lateral load-displacement curves of the improved fastener were determined via laboratory experiments.By comparing these experimental results before and after improvement,the stiffness variations of the floating rail fastener were quantified.The stress and strain distributions of each component of the floating rail fasteners before and after improvement under normal operating conditions were examined,thereby achieving a stiffness-decoupled design of the fastener.The results showed that the load-displacement curve of the floating rail fastener exhibited pronounced nonlinear characteristics under both vertical and transverse loads.The rubber wedges were designed to be filled with steel rods oriented perpendicular to the vertical principal stress and parallel to the transverse principal stress,thereby altering the stress flow path within the fastener structure.This adjustment shortened the pathway,straightened its trajectory,and consequently increased the overall stiffness of the fastener structure.After the improvement,the vertical stiffness of the new floating rail fastener increased by 1.05 kN/mm,about 15.5%,and the lateral stiffness increased by 4.81 kN/mm,about 56%.After the addition of steel rods,the pre-pressure limit of plastic deformation of the fastener system decreased from 1.688 MPa to 1.41 MPa,but the fastener system maintained stable operating performance under normal service conditions,with a pre-pressure of 0.8 MPa,and the contact area between the vulcanized test rod and the rubber wedge exhibited continuous deformation without tearing.The maximum deformation of the rubber wedge decreased from 1.17 mm to 0.89 mm,a reduction of approximately 20%.